This invention relates to a food and more particularly to a meat-like textured pet food having at least part of the casein salt replaced with a composition comprising a pregelatinized or modified amylaceous material, a non-caseinate protein source, and a substantially neutral chelating agent.
Within the class of foods known as pet foods, there are three basic subdivisions: (1) dry pet food containing up to 15 percent moisture, (2) semi-moist pet food usually containing about 15 percent to 50 percent moisture, and (3) moist pet foods containing above 50 percent moisture. The moisture is determined by considering both the water present in the final product and the water combined with the various components that make up the final product. In general, the dry pet food tends to be the most stable and requires no special handling or packaging upon distribution. The semi-moist pet food tends to be less stable than the dry pet food and requires essentially a moisture impermeable packaging system. However, the semi-moist pet food requires no refrigerated storage, and is microbiologically stable due to the presence of various stabilizing agents. The moist pet food requires stringent canning sterilization conditions. In fact, the moist pet food is canned and sterilized by retorting in the usual manner. When the can is opened, the pet food not consumed must be refrigerated to preserve it even for a short period of time. Thus, it may be seen that the dry and semi-moist pet foods are the most stable pet foods; whereas the moist is of lowest stability after the respective packages are opened. When considering palatability, generally speaking the moist pet food tends to be the most palatable and the semi-moist pet food falls somewhere in between the mosit and the dry pet food as to palatability. It follows that both as to palatability and stability the semi-moist pet food ranks in between the dry and the moist pet food. This ranking permits the semi-moist pet food to provide both shelf stability and palatability. In other words, a pet owner using a semi-moist pet food has fewer problems storing a pet food which his pet will eat. The advantages of a semi-moist pet food thus become obvious.
In semi-moist pet foods and other processed foods, casein salts such as sodium caseinate provide a highly suitable material to use as a base for a semi-moist food. This material is considered to have thermo-plastic properties and adhesive like properties and is thus both a good binder and a good extrudable material. Furthermore, this material is such a high quality protein, that it is used as a standard for determining or measuring protein quality of other protein-containing materials. It also has a high protein content, usually containing in excess of 90 percent protein. So, in addition to the processing advantages of using sodium caseinate, there is also a nutritional advantage due to the protein provided thereby. It thus becomes obvious why this material is so widely used in the food processing art and especially in the pet food art. However, the price of casein salts such as sodium caseinate is very high due to the economic conditions associated with milk processing. This price is so high, that it is not economically feasible to use high levels of caseinate in pet foods. It foods that it is desirable to develop a replacement for at least some of the caseinate in order to reduce product cost.
The unique qualities of casein salts such as for example sodium, calcium, magnesium, ammonium, and potassium caseinate render them difficult to replace. Not only must the replacement provide protein and processability, the appearance and flavor of the product must be substantially maintained. Thus it follows that the replacement for this component must also be readily processable in for the product in order to avoid substantial changes in machinery and manufacturing equipment. Also, the protein level of the replacement must remain high and the palatability of the product containing the replacement must remain substantially the same.
The most successful pet foods have the appearance and texture of meat while not actually using the expensive cuts of meat. An example of a marbled meat pet food is found in either U.S. Pat. No. 3,380,382 to Bone or U.S. Pat. No. 3,765,902 to Charter. Both of the cited patents are incorporated herein by reference. Each of the cited patents discloses a marbled meat pet food that is highly successful on the market and has a proven nutritional value for pets. A typical marbled meat product of the Bone patent contains 30 to 70 percent meat or meat by-products, 7.5 to 25 percent sodium caseinate, 15 to 30 percent sugar, 2 to 10 percent propylene glycol, 0.5 to 10 percent regular corn starch and appropriate color modifying agents. The key ingredient in this composition is the sodium caseinate, which acts as an adhesive by providing stickiness, as a binder, as a source of viscosity control, as a high quality protein source, and as a bland palatable protein source.
Thus it can be seen that to replace all of the functions of casein salts will be difficult.